The Glasgow Municipal Tramways System (Extracts from)
The Tramway and Railway World
September 7th 1911

It is now fully eight years since the annual conference of the Municipal Tramway Associa­tion was last held in Glasgow. It is a long cry from July, 1903, to September, 1911, and members of the Association who have not kept in close touch with northern developments will find when they visit Glasgow in the closing days of the present month for the forthcoming conference that many tramway developments have taken place in the interval as regards extension of lines, additions to power plant, additions to depots and rolling stock, and general expansion of the undertaking. They will also find that on the financial side the tramways show a splendid record. To aid members in their examination of one of the most successful and largest tramway undertakings of the country we here present a description which embodies some of the main points which have appeared in previous articles, eliminates those which have been superseded, and brings the information right down to the present time.

As is generally known, the tramway lines in Glasgow were never owned by a company. The original tracks were laid down by the Corpora­tion in 1871 and succeeding years, and the system was leased for 23 years to the Glasgow Tramway and Omnibus Company, who worked it by horse traction down to 1894. When the close of the lease approached the Council and the company failed to come to terms for its renewal. The result was that, under Parliamentary powers granted to the Corporation as far back as 1870, the latter determined to work the lines themselves. The late Mr. Walter Paton was appointed convener of the Tramways Committee, and Mr. John Young became; general manager. Under their guidance the new muni­cipal horse car service was started on July 1, 1894, and it was also during their rule that electric traction was afterwards inaugurated and the new system developed in a wonderfully prosperous way. Before Mr. Paton died he saw the undertaking an assured permanent success, and it was after that stage had. been reached that Mr. Young resigned in order to devote his talents to other schemes requiring powers of organisation, and Mr. James Dalrymple suc­ceeded to the general managership. When the Corporation began working the lines they ex­tended to only 31 miles of route, double track, but they rapidly increased in length, until at the present time the routes aggregate 98 1/2 miles. From the very first a profit was made after allowing for interest and sinking fund.

After prolonged investigation, involving among other things visits by deputations to the Continent and to the United States, the Town Council decided early in 1897 to try the overhead trolley wire system of electric traction, and the first line, which was regarded as experimental, was opened for traffic on October 13, 1898. It extended from the centre of the city to Spring-burn in the northern outskirts, a small temporary power-station being erected near the outer terminus. In November of the following year an extension to the south side of the Clyde came into use, giving a total of five miles of route electrically worked.

The results obtained were so satisfactory that the Corporation on January 5, 1899, resolved that the whole tramway system of Glasgow should be changed to the electric trolley wire system. Mr. H. F. Parshall, M.InstC.E. (now chairman of the Central London Railway Com­pany), was appointed consulting engineer, and on his recommendations it was decided that the tramway power plant should be altogether distinct from that for electric lighting, that one central generating station should be provided for the entire undertaking, and that the three-phase high-tension system of transmission to sub­stations distributed throughout the city should be adopted. The Glasgow tramways were thus the first in the country to adopt three-phase transmission on a large scale. A site for the power-station was chosen at Pinkston, near Port Dundas, on the north side of the city, bounded on three sides by the Forth and Clyde Canal and the Caledonian and North British Railways. The work was pushed on vigorously, sub-stations were provided wherever required, a number of the lines began operating electrically in April, 1901, and very soon afterwards the last horse car disappeared. Since then the record has been one of steady expansion in length of lines, power and distributing machinery, business done, and financial results.

PRESENT EXTENT OF THE UNDERTAKING.

At the present time all extensions have been completed, the last Parliamentary Act having been granted in 1909, and the mileage stands at 98 miles, double track. With the exception of a short length measuring one mile within the burgh of Paisley, over which Glasgow Corpora­tion have running powers, the entire track is maintained by the Glasgow tramway department. The lines in Govan, extending to 4 miles 2 1/2 furlongs, while owned by the Corporation of Govan, are leased to Glasgow ; and by agree­ment the Glasgow Corporation took over the Clydebank Tramways Order of 1901, to con­struct and work the tramways (5 miles) within the burgh of Clydebank as part of the Glasgow system'. A short length of this (2 1/2 furlongs) is, meantime, being worked by the Dumbarton Burgh and County Tramways, Limited. In all there are 59 miles of double track within the city boundary and 39 miles without. The maps here reproduced show the system, its connections with other systems, and the positions of the power-station, sub-stations, and depots. The steepest gradient is 1 in 12, and the radius of the sharpest curve is 31 ft.

PERMANENT WAY.

When the system was converted from horse to electric traction the entire track was renewed throughout. The method of construction then adopted was, briefly, as follows: A 6 in. bed of concrete was laid over the entire width of track extending to 18 in. beyond the outside of the rails ; the rails, 60 ft. long, 7 in. deep, with 7 in. bottom flange, and weighing 98 lb. per yard, were laid and fished with plates 31 in. long, having eight 1 in. bolts, the holes being staggered. The rails were laid and packed with fine concrete well rammed and Hushed to the underside of the rail. The paving, chiefly of hard granite setts, square dressed, was laid on a bed of sand, and grouted with a mixture of coal-tar pitch, and creosote oil. Four and a half miles of track laid as above, but having joints electrically welded by the Lorain Steel Company's process, are still giving satisfaction. There are also over 20 miles of track welded by the Thermit process, and at present the department are relaying Renfield Street, the part of the track where the traffic is greatest, and are having the joints electrically welded by the Tudor Accumulator Company's process. In this portion of the track anchors consisting of pieces of old rails have been embedded in the concrete every 10 ft., and the rails are held in position by bolts. The question of smooth paving has been very much in evidence of late. The results from ashphalt paving alongside tram rails in Glasgow have been rather disappointing, and in order to prevent the rutting caused by vehicular traffic, the department have introduced a smooth-dressed granite stone, 12 in. wide, along the outer side of the outside rail with good results.Wood paving has been used to some extent, but there have been laid down in the centre of the city several stretches of track paved with granite stones 6 in. wide, 9 in. long, and 6 in. deep, tooled or nidged on the surface, having perfectly square sides fitting close at the joints, and laid on a bed of cement mortar. The results, so far, have been very satisfactory, giving an almost noiseless surface.

Glasgow Tramways, Showing Position of Power-Station, Sub-Stations and Depots

A great many of the recent extensions and renewals have been laid on cross sleepers. The sleepers are best quality pitch pine, 7 ft. long, 11 in. broad on the sole, 10 in. broad on the top, and 4 1/2 in. thick, laid at 3 ft. centres on a bed of concrete 4 in. thick. The rails are fixed to the sleepers either by coach screws or dog spikes, and after being lined and levelled are boxed in with concrete up to the underside of the rail. Since 1905 the British standard rail has been adopted, using section 5 on straight track, and 5c on curves, with the standard six-holed fish plate. Various lengths of track have been laid with continuous rail joint fish plates. These have not yet been in use a sufficiently long time to express any opinion as to their merits. All fish-plated joints are bonded with two 28 in. bonds, .0000 B.and S., with cross bonds every 40 yards. Drawings of the joints are given herewith. All renewal work up to the present has been carried out during the night, as this work has chiefly been in the centre of the city where it would be impossible to use temporary lines or crossovers. This also applies to the renewals of junctions. These, as far as possible, are laid piecemeal, but where rendered necessary by alterations, even the most complicated have been renewed in one shift of five hours. The majority of the crossings in special work-are of the iron bound type, having renewable centre pieces. There are also crossings composed entirely of manganese steel. The points are of a standard length, 12 and 14 ft., constructed in cast steel with forged tongues, also in solid manganese steel. In order to have the maintenance of the track efficiently carried out, the system has been divided into sections, these varying in length with the amount of car traffic. Over each section there is one foreman with a squad of from 14 to 20 men. There are also two chief foremen, each controlling one-half of the track, with 10 foremen under him.

The depot for permanent way material is in close proximity to the Coplawhill car works. It is a yard of considerable size, where all rails, points, and crossings are stored, and where all curves, special work, etc., are built up, and to which all disused rails, points, crossings, etc., are returned. At present new offices, stores, and workshops having machine tools, rail bender, etc., are being erected. In addition, there are three subsidiary yards throughout the city, all connected up by sidings. These are used for storing setts, pitch, sand, etc. ; these materials are conveyed by trucks constructed on the double-bogie principle. These also run along­side the wharf, where setts, metal, etc., are discharged, and taken to the various points where required.

The following is the chemical composition of the rails as specified :

Carbon.. .. .. .....4 to 55 per cent.

Manganese .. .. .8 to 1 per cent.

Phosphorus .. .. Not to exceed .8 per cent.

Sulphur .. ......... Ditto.

Silicon ,, ,, ,. .....1 per cent,

PINKSTON GENERATING STATION.

The main generating station is situated in the northern district of the city, on the north bank of the Forth and Clyde Canal, at Pinkston. The ground, which was purchased on May 4, 1899, extends to 18,997 sq yards. The building consists of a steel framework cased in brick and plaster. The building is 244 ft. long by 200 ft. broad, and 88 ft. high inside. The station is divided into three sections, viz., boiler room, 244 ft. by 84 ft.; engine room, 244 ft. by 75 ft. ; auxiliary plant room, 244 ft. by 40 ft. The height of the boiler room is 70 ft., that of the engine room 64 ft., and that of the auxiliary room 52 ft. The two chimney stacks are built of brick, with ornamental stone and terracotta mouldings. The total height of the stacks is 263 ft., the internal diameter is 16 ft., and the width across the base is 50 ft. Boiler Room. The boiler room is equipped with twenty-two Babcock and Wilcox water-tube boilers, with the Scotch type furnace, with internal superheaters and the makers' mechanical chain grate stokers. The boilers are arranged in eleven batteries of two boilers each, five batteries on one side and six on the other. The original equipment consisted of sixteen boilers capable of producing 20,000 lb. of steam per hour at a working pressure of 160 lb. per sq. in., with a superheat of 75 deg. Fahr. The boiler tubes are 18 ft. long and 4 in. in diameter, with a heating surface of 5,173 ft., the grate area being 63 sq. ft. The six larger boilers installed in 1909 have a capacity of 25,000 lb. of steam per hour at 160 lb. pressure, with a superheat of 130 deg. Fahr. These boilers are fitted with tubes 18 ft. long aid 4 in. in diameter, with a heating surface of 6,182 sq. ft., the grate area being 100 sq. ft. Each side of the boiler house, with its batteries of boilers, is equipped with an independent coal and ash conveyor, coal storage, economiser, flue, and shaft.

The motors driving the stokers are placed in the basement of the boiler room. There is one direct-current motor at each end and one alternating-current motor in the centre of each of the common driving shafts, the two driving shafts running the whole length of the boiler batteries, one on each side under the floor, so that each shaft can, in case of emergency, be driven from any of the motors. The water for the boilers is supplied from the Corporation mains to two storage tanks placed on girders between the two chimneys, and they hold 36,000 gallons. Each of the two fuel economisers is capable of dealing with 18,000 gallons of water per hour and raising its temperature from 90 deg. to 160 deg. Fahr.

The furnace gases discharge into two overhead flues, constructed of Siemens-Martin steel plates. The length of each flue is 242 ft. and the width 8 ft. The flues are covered throughout their entire length with asbestos and magnesium lagging respectively.

Coal and Ash Handling. Coal is brought to the generating station by two railways the North British and the Caledonian the lines terminating in specially constructed sidings. The outside coal bunkers have a capacity of about 4,000 tons. There are six tracks and eight hoppers for the Caledonian Railway (high level), and one track and two hoppers for the North British Railway (low level). The railway wagons are tipped directly into the bunkers by two electric locomotives fitted with swivelling cranes, and all shunting operations are carried out with the same locomotives.

The coal is carried from these outside bunkers to storage bunkers built over the top of the boilers by two mechanical bucket conveyors, built by the Mirrlees Watson Company. The bunkers over the boilers have a capacity of about 2,400 tons. Each conveyor can handle 50 tons per hour, and runs at a speed of 45 ft. per minute. The coal passes from the overhead bunkers into the boiler hoppers through specially designed shoots with weighing arrangements. The ashes are handled by the coal conveyor, the buckets being filled by four fillers from shoots under the boiler ash-bins. The conveyors take the ashes up to the top of the boiler room, and discharge them into a specially constructed ash-bin built at the end of the boiler room, from which they are shot into carts for removal. The boiler feed-piping is arranged on a double ring system, either the steam or electric pumps being able to supply the boilers. The water is taken from the hot wells, and passes through meters to the economisers and into the boilers, the water passing from the condensers through a Harris-Anderson water purifier back into the hot wells, which are replenished from the storage tanks. The steam piping is extremely short and simple, one main header running the whole length of the boiler house ; from which the necessary branches are taken.

Engine Room. Two overhead electric three-motor travelling cranes, of 75 ft. span, are in­stalled in the engine room, each being rated to lift 50 tons. The original steam plant consists of four three-cylinder vertical compound engines rated at 4,000 h.p. each ; two two-cylinder vertical cross-compound engines rated at 800 h.p. each, and six two-cylinder compound high-speed engines of the enclosed type rated at 100 h.p. each. Two of the four main engines were made by the Allis Company of Milwaukee, and the other two by Messrs. Musgrave and Sons, Bolton. Messrs. D. Stewart and Company, Glasgow, supplied the two 8oo-h.p. engines, and Messrs. W. H. Allen, Son, and Company, Limited, Bedford, the six small engines.

The Allis engines are of the Reynolds-Corliss type, and run at 75 revolutions per minute, with 150 lb. steam pressure. The cylinders measure 42 in., 62 in., and 62 in. in diameter, with a 60 in. stroke. The cylinders are furnished with the Reynolds-Corliss automatic double-ported valve gear, each with two eccentrics. The governor is of the weighted type, operating both high and low-pressure cylinder valve gears. The high-pressure cylinder is steam jacketed, and a reheater receiver is fitted between the high and low-pressure cylinders. The flywheel is 24 ft. in diameter, and weighs about 220,000 lb. The total weight of the engine complete is about 700 tons, and, with the generator, about 790 tons.

Engin Room Vertical Engins, Generators and Turbo-Generator

The results of the official tests on No. 1 engine showed a steam consumption of 12.2 lb. of steam per 1. h.p. hour, and on No. 2 engine a consump­tion of 12.4 lb. per i.h.p. hour. The Musgrave engines are of a somewhat similar design to those previously described. The sizes of the cylinders are: High pressure 42 in., low pressure each 60 in. in diameter, with a 60-in. stroke. The shaft is in two pieces, together weighing about 82 tons. The valves are of the Corliss cylindrical type, with Musgrave trip motion, worked by eccentrics from the main shaft. The governing gear is similar to that on the Allis engines. A reheater is fitted between high and low-pressure cylinders. The steam consumption during the official trials in June, 1902, showed that the steam per i.h.p. hour was 13.4 lb. for No. 3 engine, and 13.2 lb. for No. 4 engine.

Owing to the increased requirements for power, it was decided in 1907 to install a steam turbo-alternator. A 3,000 kw., 1,500 revolutions per minute turbine of the Brown, Boveri-Parsons type, manufactured by Messrs. Richardsons,Westgarth, and Company, Limited, of Hartlepool, was finally installed and put on load in June, 1909. This turbine is specified to give 25 per cent, overload continuously without the use of a bye pass, and 50 per cent, overload with the bye pass in action; the guaranteed steam consumption at full load is 14.85 lb. per kilowatt-hour, with a steam pressure of 150 1b. per square inch, and steam superheated to 300 deg. C. The turbine is provided with the makers' emergency cut-out gear, which automatically releases a helical spring on the stop valve spindle, thereby closing the stop valve whenever the speed exceeds a certain predetermined value. The preliminary official steam tests taken on this turbine show that the makers are well within their guaranteed figures. Owing to the economical results obtained from the turbine, it has been decided to install another turbine of 5,000 kw. capacity.

The 800-H.p. Stewart engines are of the two-cylinder, vertical, cross compound type. The six auxiliary Allen engines are of the high-speed, compound, two-crank, enclosed type, rated at 100 h.p. at a speed of 300 revolutions per minute.

Automatic Oiling System. The " Siegrist " automatic oiling system is installed on the Allis, Musgrave, and Stewart engines. The cylinder oil and engine oil are pumped by steam pumps from tanks in the oil filter room to an overhead divided tank. From this tank the oil is delivered by steam pumps to the separate engine units. After lubricating the engines, the oil gravitates from the crank pits through the filters to the engine oil tank in the oil filter room.

Generators. The four three-phase generators for the reciprocating steam engine sets were sup­plied by the British Thomson-Houston Company, Limited, and built in America by the General Electric Company. Each machine has a nominal capacity of 2,500 kw. at 6,500 volts when running at a speed of 75 revolutions per minute. The machine has 40 poles, thus giving a frequency of 25 cycles per second. The machines have stationary armatures, the armature frame being arranged on sliding foundation plates, allowing the frame to be moved clear of the field. The construction of the armature windings allows of any coil being removed and replaced without disturbing more than six adjacent coils. There are 120 coils, each coil having 18 turns. The revolving field pole-pieces are built of sheet iron, securely fastened to the periphery of the flywheel. The field coils are made of strip copper wound on edge.

The normal excitation of the field at full non-inductive load is 250 amperes, or, at full induc­tive load, at 80 per cent, power factor, 345 amperes. The excitation current is taken from the 100-volt exciter circuit. The generators are capable of carrying 25 per cent, overload for a long period, and are guaranteed to stand 50 per cent, overload for 15 minutes without injury.

The two-pole three-phase alternator for the 3,000-KW. turbine set was supplied by Messrs. Brown, Boveri, and Company. At unity power factor the output is 3,000 kw. at 6,600 volts ; it has an overload capacity of 25 per cent, for two hours and 40 per cent, for one half-hour, with a maximum temperature rise on full load of 45 deg. C. The full load efficiency is 95 per cent. Cool air, delivered under pressure after passing through a filter, is drawn into the windings of the machine at both ends, the air entering at the base and being discharged at the top.

The 500-volt. B.T.H. direct-current generators (which are coupled direct to the Stewart engines), when running as shunt machines at 500 volts, are rated at 500 kw., and at 600 kw. when running as compound machines at 600 volts at a speed of go revolutions per minute. These sets are used to supply current to the system during the time the cars are not in service, and are also used, in conjunction with two rotary converters installed in the pump room, to relieve the main engines at times when the load on the power-station is slightly more than a full load for the main generators running. The six auxiliary generators were also supplied by the British Thomson-Houston Company, and have a capacity of 50 kw. each at 100 volts when running at a speed of 300 revolutions per minute. The machines are shunt wound and employed to excite the fields of the main generators, and to supply current for the station lighting.

Auxiliary Room. The auxiliary room contains the whole of the condensing plant in connec­tion with the reciprocating sets in the engine room, and also the boiler feed pumps, rotary converters, and the water purifier. The con­densing plant consists of five surface condensers built by the Mirrlees Watson Company. There are four condensers capable of dealing with 60,000 lb. of exhaust steam per hour, and one condenser capable of dealing with 24,000 lb. per hour. Each condenser is provided with a three-throw Edwards air pump driven by a motor. The circulating water centrifugal pumps are also electrically driven, and were supplied by Messrs. Mavor and Coulson. Four of the pumps have a capacity of 240,000 gallons of water per hour, and one has a capacity of g6,ooo gallons per hour. Each pump receives the water from the canal through separate pipes about 25 ft. long, and discharges into a common pipe leading into the canal.

Five feed pumps are installed four electric ally-driven ones by the Mirrlees Watson Company, and one steam pump by Messrs. G. and J. Weir, Limited. The first have a capacity of 8,000 gallons of water per hour against a steam pressure of 160 lb. The Weir steam pump has a capacity of 16,000 gallons per hour when running at its normal speed of 12 double strokes per minute. The feed water purifier supplied by Messrs. Harris, Anderson, and Company, has a capacity of 22,000 gallons per hour. The feed water from the condensers is received into a mixing tank, where alum and soda are added, and passes through a series of tank filters packed with special wood fibre.

Auxiliary Room

The two rotary converters installed in one corner of the auxiliary room are used for two purposes, viz., converting the three-phase high-tension current into 500-volt direct current for the power supply of the generating station when the direct-current generators are not running; and also, as previously mentioned, to convert the 500-volt direct current received from the Stewart setts into three-phase current.

The condensing plant for the 3,000-KW. turbine is capable of dealing with 50,000 lb. of steam per hour, and is fitted with a "Lea" recorder. The whole of the plant was supplied by the Mirrlees Watson Company, and practic­ally is on the same lines as that previously described. Two additional boiler feed pumps are placed alongside this condenser.

Switchboard . Considerable trouble was given by the original switch gear at Pinkston, the air-break switches being chiefly at fault, and in 1904 it was decided to scrap this gear and install a modern electrically-controlled system with oil-break switches. Owing to want of space, considerable difficulty was met with when drawing up the plans for the new installation. It was finally decided that the Corporation engineers would be responsible for the designs of the general installation, and on this arrange­ment contracts for the generator and rotary transformer switches were let to the British Thomson-Houston Company, and for the feeder switches to the Westinghouse Company.

The installation is arranged on three floors. The ground floor contains the dividing bell-mouths for the incoming generator and rotary cables, the outgoing feeder cables to the sub­stations and to the generating station of the Corporation electricity department; also all instrument transformers, synchronising trans­formers, and the cable spark-gaps. The second floor, on the engine room floor level, contains the main oil switches, and the third floor carries the two bus-bar chambers extending the whole width of the engine room, with oil-break switches at each end for inter-connecting the two sets of bus-bars and forming a ring bus-bar. In the design of the switch gear, care has been taken to isolate each phase by a 4 1/2 in. brick wall. To enable the connections of the switch gear to be readily followed, and to give at the same time a short description of the type of gear installed, a start is made from the main generators. Two 0.2 sq. in. three-core cables run in ducts from each main generator through the foundation of the machines to the ground-floor compartment of the gear. These cables end in two simple lead bell-mouths, filled in with paraffin wax, with a layer of hard bitumen over the top of the wax. From the lead bell-mouths three single-core rubber cables are taken through porcelain insulators to their respective phase compartments. A series transformer is inserted in each phase, these transformers supplying the current to the ammeters, watt-meters, etc. The cables then pass to the isolating switches and to the incoming terminals of the British Thomson-Houston non-automatic generator oil-switch, and at this point tappings are taken off each phase to three sets of potential transformers supplying current to the three independent synchronising circuits, and to the potential transformers for the power factor indicators. The main oil switch is of the well-known British Thomson-Houston type operated by a series motor. The switch has a carrying capacity of 500 amperes.

Instrument and Control Boards in Pinkston Power Station

The outgoing cables are led up the back of the oil switch to knife-pattern isolation switches, thence to the bus-bar chamber on the second floor, the cables passing through the floor in porcelain insulators to the double set of selector switches. Solid copper connections are taken from these selector switches through the brick­work on to the main and auxiliary bus-bars. The main bars are in sections, one generator being coupled to each section; these sections may be interconnected by knife section switches. From each section of the main bus-bars five three-core high-tension feeders are taken off. The supply to the feeders is taken off the main bus­bar by single-core rubber-covered cables, each one of these cables supplying two feeders (with the exception of the cables taken off the live end of the selector switches on Nos. 2 and 3 generators). These single cables pass through the floor on to the top jaws of knife-pattern isolating switches, and it is at this point that the connections are taken through the brickwork to the knife isolating switches immediately behind the particular isolating switches in question. From the isolating switches the circuit is con­tinued to the automatic oil-break feeder switches. These switches were made by the Westinghouse Company, and both the closing and tripping circuits are controlled by solenoids. Passing through the switch, the cables are carried through the switch room floor on to the top jaw of one of the twin isolating switches, the bottom jaws of these switches being coupled together. One of these switches controls the connection to the outgoing feeders, the other controlling the circuit to the spark-gaps, which are fixed on the outside walls, being connected up to the switches by small cables passing under the roof. The main circuit is continued from the isolating switches through series transformers to the bell-mouths of the three-core feeder cables.

The main alternating-current instrument board is installed on a gallery in the engine room, the gear being mounted on 24 polished marble panels. There are two sets of 100-volt bus-bars carried on the back of this board, one set carrying the current for the excitation of the main generators, and the other set supplying the station lighting and the power for the electrical operation of the high-tension circuit breakers. The well-known "Tirrill" regulator, supplied by the British Thomson-Houston Company, is fixed on this board, the instrument automatically controlling the voltage of the main circuit independently of speed changes or variation in load.

The generator control desk is installed on the gallery in front of the main alternating-current switchboard. There are six generator panels, each with its various controls and instruments. At the ends of the control desk are two panels carrying synchronising voltmeters, the synchro­nism indicator, and two synchronising lamps.

Interior of Partick Sub-Station

The electrically-operated engine room tele­graphs were supplied by Messrs. Evershed and Vignoles. They are used for signalling orders to the engine driver at each of the main generators.

The direct-current 500-volt switchboard is erected on the engine room floor level underneath the high-tension operating gallery previously mentioned. This board controls the 500-volt generators, rotary converters, night load feeders, and the station power supply.

SUB-STATIONS.

There are in all six sub-stations situated in different districts of the city, containing 26 units, as under :

Each unit consists of three transformers of 200 kw. each, and one rotary converter of 500 kw. Each sub-station has two switchboards, one for alternating current and the other for direct current. All high-tension switch gear is erected in separate switch rooms, which contain the necessary oil switches, etc., operated by remote control from the alternating-current switchboard.

Each set of transformers, which are connected in mesh, are placed in a brick chamber, com­pletely isolated by brickwork and iron floors from the rest of the plant. The transformers are of the oil-cooled type. Tappings are taken off the primary winding, so that with 6,500 volts on the
primary, the windings can be plugged so as to give 310, 330, or 350 volts on the secondary winding. The rotary converters are each of 500 kw. capacity. They are six-pole machines, running at a speed of 500 revolutions per minute. The machines are over-compounded to give 500 to 550 volts. The efficiency at full load is 95 per cent., three-quarter load 94 per cent., half load 92.5 per cent. On the alternating-current end of the rotary shaft a io-h.p. starting induction motor is fixed for purposes of running the rotary up to synchronism. On the other end of the shaft a continuous-current booster is fixed for dealing with part of the return current. The booster is rated at 30 kw. at 50 volts, at a speed of 500 revolutions per minute. The fields are excited by a portion of the feeder current. Shunt resistances are so arranged that 200, 400, or 600 amperes can be passed round the field, or the field can be short circuited. All the electrical equipment was supplied by the British Westinghouse Company, except the direct-current switchboard in the Rutherglen sub-station, which came from the British Thomson-Houston Company.

CABLES.

From the main power-station run 22 three-core extra high-tension cables, four to each of five sub-stations and two to the electricity depart­ment, the cross-section area of each core being from .10 sq. in. to .2 sq. in. The cables are insulated with manila paper impregnated with

an insulating oil and lead sheathed. In addition, single core 500-volt direct-current feeders are run to each sub-station, these cables being used for supplying current to the system during the hours when there is little or no demand for power for traction purposes.

The three-core cables enter the sub-stations from ducts into a cable race, and are then split inside trifurcating heads into three separate rubber-insulated single cables, and thence led to the feeder oil switches in the high-tension switch rooms.

From the direct-current switchboards of the sub-station the 500 volt feeder cables are led along the cable race into the ducts to the various feeder pillars in the streets. These feeder cables (some 80 in number) have cross sectional areas from .8 sq. in. down to .4 sq. in., some of the feeders to heavy sections being duplicated.

Cable Transporter Car

The distributor cables, ranging in size from .8 sq. in. to .2sq. in., run from the feeder pillars to numerous distributing switch pillars. Through­out the central parts of the city, adjoining feeder areas can be interconnected by cables running between the nearest switch pillars, a system of ring mains being thus formed, so that any necessary repairs in case of the breakdown of any cable can be speedily carried out without causing undue delay to the traffic.

Negative feeders, numbering 31 in all, used for boosting the return current from the rails, are laid to the heavily-loaded and more distant parts of the system. These cables have a cross sectional area of .8 sq. in. or .6 sq. in. each, and a total area of 21.0 sq. in.

The total length of cables used in connection with the tramways amounts to about 469.16 miles, made up as follows :

DUCTS AND MANHOLES.

Most of the ducts are formed of a riveted lapping of sheet iron of No. 25 S.W.G. (i.e., •02 in. thick) lined with a special cement 9/16 in. thick. The ducts are laid between the tramway tracks. The bottom tier is laid on a bed of con­crete 3 in. thick, and each tier is covered with cement, while concrete is laid at the sides and on the top to a depth of 3 in., the whole forming a nest of cement-lined pipes embedded in a solid mass of concrete. In some parts of the city Doulton conduits and ordinary fire-clay pipes, and in others iron pipes are used.

The manholes are built of brickwork, the roof being supported by old tramway rails. The manholes are placed at extreme distances of over 400 ft. apart on straight runs, to a minimum of about 50 ft. on sharp curves.

Under the Forth and Clyde Canal the cables are carried in a tunnel surrounded by concrete, and lined with cast iron tubes.

On some of the extensions Sykes and fibre ducts have been used, and on others the cables have been laid solid in Howard asphalt troughing.

TELEPHONES.

A very complete system of telephones has been laid down, and may be divided into the following circuits : (1) Head office to main power-station, sub-stations, car sheds or depots, car

works, and residences of the principal officials and their assistants ; (2) head office to numerous telephone pillars erected on the streets, keys of which are carried by every car and each inspector and timekeeper ; (3) power-station to each sub­station ; (4) "emergency system" from each sub-station to every feeder and distributing switch pillar within its own area of supply.

OVERHEAD EQUIPMENT.

The overhead equipment for the original tramway system was carried out by the British Westinghouse Company. On subsequent exten­sions the work has been executed by the staff of the tramway department. Centre poles are used on several short lengths of route, but on all the rest of the system span-wire construction has been adopted. Wherever possible the span wire is attached to the buildings by means of rosettes on either side of the street.

Moter Tower Wagans

The trolley span wire is of 7 strand No. 12 S.W.G. with a breaking strain of 4,000 lb., and the guard span wire of 7 strand No. 14 S.W.G. wire with a breaking strain of 2,000 lb. The guard wire is earthed at each end of every eight spans. The poles are earthed to the rails with rail bonds made up to the required length with ordinary trolley wire. The system is divided into half-mile sections.

Most complete arrangements are in force for the maintenance and repair of the overhead equipment. In recent years the horse tower wagons have been displaced by those of the motor variety, with very satisfactory results. A view of these motor wagons is given above.

Standard Top-Covered Vestibuled Car

Testing Car

The total number of cars owned by the Corporation is now 803, as under :

Top-covered Cars .. .. .. .. ....................... 621

Double-deck Cars (without top-covers) .. .. 71

Converted Horse Cars .. .. ........................ 110

School Car .. .. .. .. .. ................................... 1

Total .. .................................................... 803

The whole of the cars, with the exception of about 80, have been built and equipped in the Corporation car works.

The double-deck car with top roof is carried on a single truck with 6 ft. wheel base, weighs about 9 tons 15 cwt., and stands 16 ft. 1 in. high over all. The body is 17 ft. over all, with 6 ft. platforms, the inside having a seating capacity for 24 passengers. The upper body of the car is 17 ft. over all, and is fitted with garden
seats, accommodating 28 passengers inside under cover, and 10 passengers on outside seats. All cars have the trigger gate type of life-guard. Fifty additional cars are in course of construction. The Standard Car. The covered car with vestibules has now been adopted as the standard car of the system. In its evolution from the old type of open-top car a great many alterations had to be made. The car body is all that remains of the old type. When it was decided to have top covers it was found that the platform had to be lengthened to allow of an easily ascended stair being led up to the canopy. This necessi­tated the platform bearers being lengthened and new dashes made, wiring to controllers spliced, and all platform gear made correspondingly longer. The canopy and upper part are new. When covered cars had been in service for some time the question of vestibules was considered. Vestibules were fitted to several top-covered cars, and were so satisfactory that it was decided to fit vestibules on all cars. These additions and alterations to the car raised another question that of stability. It was found that the increased length of platform and the added height had altered the centre of gravity, and, therefore, the car pitched more than was notice able on the smaller type of car. The remedy for this was found to be a truck with longer wheel base, and as this truck must combine stability without undue wear on the wheel flanges or rails at curves, experiments were made, and it was found that the present truck lengthened to 7 ft. wheel centres gave satisfactory results. This alteration meant that the underframing had to be altered to accommodate the wheels. The platform bearers had to be shortened to clear the wheels, and the magnetic brake and hand-brake gear altered to suit the increased length of wheel base.

All improvements are now in hand, and cars, in the course of a few weeks, will be turned out at the rate of five per week, fitted with lengthened truck, top roof, and vestibules.

CAR SHEDS.

There are in all nine car sheds, situated as under:

West End...................... Partick.

North ........................... Possilpark and Maryhill.

East End ........................Dennistonn, Whitevale, and Dalmarnock.

There is accommodation at these depots for 1,117 cars. Newlands and Langside can each take 180 cars. Most of the depots were originally built for horse cars, and were afterwards altered. The number of tracks in all the depots is 161, and the total length of these tracks is over eight miles. At all the sheds there are office accommodation, lavatories, washing room, baths, kitchen, recreation room, gymnasium, etc. The latest depot, built at Newlands, is much on the same lines for car storage as the others. In view of the fact that a great percentage of cars are now covered, gangways have been suspended from the roof along the entire length of each line, thus enabling the outside of cars to be cleaned without the use of steps. The principal feature at this depot is the heating arrangement. Hot water, especially in winter, is an absolute necessity if cars are to be kept clean.

A vertical boiler has been installed, which by steam heat through one calorifier supplies hot water to taps conveniently placed throughout the depot, the temperature of the water being 120 deg. Fahr., or higher, if desired. As there is a return pipe to the calorifier, a continuous circulation of water is kept up, so that hot water can be drawn from any tap without loss of time. The capacity of this calorifier is 750 gallons of water per hour. Another calorifier supplies hot water to radiators, which heat up the depot buildings including hall (seating 300 persons), kitchen, recreation room, cleaners' store, depot store, and workshop, and in addition to these buildings there are a fully equipped lavatory and bathrooms supplied with hot water from the domestic supply. This hot water installation requires very little attention, the boiler feed and temperature of calorifiers being automatically regulated.

CAR WORKS AND CAR BUILDING.

A ground plan of the large and complete car building and repairing works at Coplawhill, together with internal views, are here given.

The following is a list of the staff employed at the car works:

The various departments are all well equipped with machine tools, etc. The whole of the cars undergo an annual examination and overhaul in addition to repairs which they at any time require. The number dealt with at a time is proportioned so that the whole may be got over in the year.

In the construction of car bodies great care is exercised in selecting timber of the very best quality. For the general framework the best dry Moulmein teak is largely used. The under­framing is of massive design. The roof ribs are of best English ash, every alternate rib having mild steel carlines 1 1/4 in. by 1/4 in. on each side. The roof is double lined, and between the linings canvas, thoroughly stretched and saturated with genuine white lead, is placed. The panels are of Honduras mahogany. The inside finish­ing is in teak panelling with mahogany mouldings, the ceiling being of three-ply bird's-eye maple, picked out in gold lines and ornamental corners.

Arrangement of Duties. Motormen and con­ductors are divided into three classes :

1 Men operating workmen's or early morning cars. These men are promoted by seniority. They always report early, and always finish early, being confined to the early morning cars alone.

2.—Men on regular duties. These men operate, in their turn, each of the regular duties allocated to the depot at which they are employed, excluding, of course, the early morning cars.

3.—Spare men. These men are employed on the spare list, and advance according to seniority to any vacancies on the regular duties.

For early morning and regular men the duties are changed weekly. Spare men are paid full wages according to scale from the day on which they begin to learn their duties. If there is no work for them on a car they are employed about the depot or on the road at some useful work, and receive a full day's wage for each day they are on duty.

Ticket Check. The ticket check system in operation is of the usual bell-punch type, and a staff of inspectors are employed for boarding the cars for checking purposes.

Two-Stage Fare. On January 15, 1911, a special " two-stage" fare was introduced. A passenger, on paying 1 1/2d., receives from the conductor a yellow ticket which entitles him to travel two consecutive 1/2d. stages on the car on which it is issued, an average distance of 1.16 miles. The ticket is retained, and on production at any future time on any car on any route, is valid for two stages on the second car. The result of the introduction of this fare was reported on by the general manager recently. The average number of two-stage tickets issued is approximately 315,000 per week. As this figure has remained stationary for some time, it may be taken as a maximum.

Fares. There are no special fares for workmen, all passengers on the Glasgow system paying alike.

Cash Collection. Some years ago arrangements were made that conductors should pay in cash only on the finish of the relief, instead of each journey as formerly, and the tendency recently has been to do away, as far as possible, with cash offices except on specially busy routes where they are still necessary as a relief to the work of the depot clerks. The result of this change has enabled the department to cut down the lying time at termini to a minimum, and has caused considerable saving in the expenses of cash collection and check.

Bonus to Motormen. A bonus of 26s. is paid to each motorman on the steady driving list whose record is otherwise satisfactory, and who has been free from collision or accidents for a period of half a year that is, 26 clear weeks. This, of course, applies only to accidents which have been caused or contributed to by the motorman through neglect or carelessness. The system of working the bonus is exceedingly simple. When a man is transferred to the driving list a premium or bonus card is issued to him. This card is signed by the traffic superintendent, and when a man is called to the head office in connection with any accident he has to bring the card with him. If the super­intendent is of opinion that the motorman is to blame an entry is made on the card, and whenever a motorman finds, from his card, that he has 26 weeks clear without an entry he forwards the card to the head office, and the bonus is paid with the next week's wages, the card being returned to the motorman, who signs for the receipt of the bonus. There is thus very little trouble in working the system, as the men can be relied upon to claim the bonus whenever it falls due. The result of the introduction of this scheme has been very satisfactory, and considerably over go per cent, of the men regularly earn this bonus, which is equivalent to an extra 1s. per week on their wages.

Training of Traffic Staff All men employed in the traffic department enter the service as con­ductors. The period of training for a conductor extends to eight days, this time being spent on a car under, the tuition of an experienced conductor. During the period of training the learner is frequently visited by ticket inspectors, and at the finish of the course he is put through an oral examination to test his qualifications. If satisfactory, the practice note is signed by the teacher, the ticket inspector, and the depot clerk, and the man is placed on the spare list. All conductors, after serving a period varying from 12 to 18. months, are sent to the motor school. The school is under the control of the traffic superintendent, and the instruction is given by a qualified electrical engineer. Four or five days are spent in the school, and the embryo motorman is then put on the road under the charge of a skilled motorman. Two motor inspectors, under the chief motor in­structor, pay special attention to the learners, and after a period on the road they are sent back to the school to undergo a preliminary examination.

Glasgow Corporation Tramways School for Motormen

At this preliminary examination, it is easily ascertained whether the learner is likely to turn out a satisfactory motorman or not. If there is any dubiety, the man is not retained in the service. If the progress has been satisfactory, however, he goes back on the road again, and at the end of 14 days undergoes a final examination at the motor school. If satisfactory, he is sent to drive a car for 30 days by himself, and if at the end of this time the officials are still satisfied as to his ability, he is passed as a qualified motorman. Periodical examinations are conducted at the depots to see that the men retain the knowledge which they have gained in their early instruction, and any men who fail to answer the requirements are either discharged or sent back to the school for further instruction at their own expense. Con­ductors who have qualified as motormen are required to put in, at least, 14 consecutive days each year as motormen, to give the men an opportunity of keeping familiar with the duties. All employees now receive six days holiday per annum with pay.

MEN'S AMBULANCE TRAINING.

Special encouragement has been given to the men to take training in ambulance work. This year a team representing the department won the Cowan Cup, which is the most important ambulance trophy in Scotland. This is the fifth time this trophy has been won by the Corporation tramway employees.

UNIFORMS.

All the traffic staff, including motormen, con­ductors, ticket inspectors, timekeepers, trolley and point boys, are supplied with uniform as under :

The men engaged at the overhead repairs are supplied with leather rainproof coats, gloves, and rubber boots, and these are repaired when required. All the permanent way inspectors are supplied with a waterproof coat each year.

FRIENDLY SOCIETY.

In connection with the department there is a Friendly Society, each member contributing 6d. weekly, to which the Corporation adds 4d., making iod. weekly set aside for each member. The Friendly Society has a membership of 4,000. Membership is voluntary and confined to em­ployees of the department, but it is open to all grades of the service. The benefits given are: In cases of sickness 15s. per week for the first six months, and 10s. for second six months, and 5s. per week for following year; at death of a member £20 ; at death of a member's wife £5 ; medical attendance and cars on each route, the car-mileage on each route, the total receipts, and the receipts per car-mile. Another statement giving similar information for the week is submitted to him with a note of the number of passengers carried at each fare. In addition to the calculation per car-mile, the receipts on each route are brought out per car-hour. Numerous statements are submitted to the general manager weekly, giving full details of all expenditure. The wages paid amount to over £7,000 weekly. The total amount paid is allocated to the various accounts chargeable, and worked out per car-mile and per car-hour. The amount expended in the maintenance of permanent way, power plant, cars, etc., is also worked out per car-mile, so that from week to week all items of expenditure can be carefully watched and regulated. Copies of all these statements are prepared for the heads of the various departments for their information and guidance.

FINANCIAL.

The following is an abstract of the revenue and expenditure for the year to May 31, 1911, as compared with the figures for the preceding year:

The number of car-miles run during the year was 21,704,237, and the number of passengers carried reached a total of 237,967,307.

The total capital expenditure from 1871 to 1911 amounted to £3,921,406 .10s. 1d. This sum has been written down to £1,800,259 3s. 1d.

In the accounts for the past year revenue has been charged with £85,450, to meet the wear and tear of the track. This sum is calculated at the rate of £440 per mile of single track, and is in addition to the usual expenses for ordinary maintenance. The sum laid aside will be sufficient to completely renew the track every ten years.

In addition to the above, the revenue of the year is charged with sums to meet depreciation at the following percentages on the original cost:

The total amount set aside to meet deprecia­tion and permanent way renewals for the year to May 31, 1911, was £202,579. These sums are charged in addition to the cost of ordinary repairs, and also in addition to the statutory sinking fund of £89,794. After meeting all work­ing expenses and fixed charges the department had still a net profit of £68,678, which in terms of section 30 of the Glasgow Corporation Act, 1909, falls to be paid over to the Common Good Fund of the city. The following comparative records show the great expansion of the Glasgow system. In connection with them it will be noted that the payments to the Common Good have gone up enormously. The reason is that until the passing of the Act of 1909 the Corporation only paid to the Common Good a part of the tramway profits, the rest going into the special depreciation fund. Since the Act mentioned, however, all profit left after making allowance for ordinary depreciation goes into the Common Good.